Scott, IMHO an A-Just-O jig is a piece of (insert 4 letter word here)

It's a pain to poke the jig holes in the ribs, hard to match up with the plans and it's really bad if you have taper or sweep. Best thing to do is get a flat table, put a balsa building board on top (available at Tower) and build as normal with pins and plans. As long as everything is flat it's no problem at all.

Same with the fuselage. If the fuselage shape is complicated most designers include a way to line everything up. Usually a bottom or top keel piece.

Have a blast... building your own plane is much more fun than ARFing it.

Don